The fruitless (fru) gene in Drosophila melanogaster is a multifunctional gene having sex-specific functions in the regulation of male sexual behavior and sex-nonspecific functions affecting adult viability and external morphology. While much attention has focused on fru's sex-specific roles, little is known about its sex-nonspecific functions. The embryonic central nervous...
Courtship and copulation behaviors in Drosophila melanogaster males are regulated by sex-specific products from the gene fruitless (fru). Male-specific FRU proteins (FRU[superscript M]) are putative transcription factors of the BTB-ZnF family that likely act by controlling development and maintenance of the neural circuitry used during male sexual behavior. However, which...
Soil respiration, or the combined CO₂ emissions from roots and soil microorganisms, constitutes one of the largest losses of carbon (C) from terrestrial ecosystems. The major drivers of soil respiration, which include soil moisture, temperature, and substrate quality, have been known for some time. Nevertheless,
correlations between these drivers and...
Canopy structure has a significant impact on the canopy hydrology of
Douglas-fir forests in the Pacific Northwest (PNW). Whole canopy rainfall
interception was measured for young Douglas-fir forest and compared to an
old-growth Douglas-fir forest. The old-growth forest had significantly greater
canopy water storage capacity (5) and direct throughfall fraction...
Soils are the largest terrestrial pool of carbon, therefore it is critical to understand
what controls soil carbon efflux to the atmosphere in light of current climate uncertainty.
The primary efflux of carbon from soil is soil respiration which is typically categorized
into autotrophic and heterotrophic respiration. These two components...
The goal of this dissertation was to improve our understanding of age-related constraints on aboveground production of forest trees. Previous research suggesting that carbon uptake of old trees is hydraulically constrained by tree size was used as the
springboard for this research. Three specific working hypotheses were investigated: 1) compensation...
Exotic ponderosa pine (Pinus ponderosa Doug. ex Lawson) plantations are being planted within the natural distribution area of cordilleran cypress (Austrocedrus chilensis (D.Don) Pic. Ser. et Bizzarri) in Patagonia, Argentina. The productivity of these exotic plantations is much greater than that of native forests, suggesting greater water use. Before these...
The links between forests, streamflow, and climate are poorly understood. Despite hundreds of studies over the past 60 years, fundamental questions of forests' effects on the hydrologic cycle remain unanswered. The hydrological cycle involves mutually-dependent biological and physical processes that operate at multiple scales of time and space, and this...
Heartwood can have properties that are distinct from sapwood,
including resistance to insect and microbial attack. Despite the practical
importance of heartwood formation in trees, a review of the literature revealed
that little was known about the effects of environmental factors on heartwood
quality or how variations in heartwood properties...
This study examined the decay resistance of the pine and maple components of wood plastic composites (WPC' s) of varying thicknesses exposed on several culture media to wood decay fungi under laboratory conditions. The ability of malt agar extract (MEA), potato dextrose agar (PDA), amended basal salts, sawdust (maple and...